Abstract
SPLINT (SPLine INTerpolation) is a BASIC microcomputer program that uses electrophoretic data on the migration distances of DNA fragments of known size to approximate the relationship between distance moved and DNA fragment size by a piecewise cubic spline function. This function places all standards exactly on the calibration curve and then determines from it the sizes of other fragments in the gel. Special advantages of this program include the use of a digitizer to enter the fragment positions directly from a gel photograph and the optional generation of a graph of the approximating function plus the placement on it of points from any specified gel lanes.